- I configured the local wifi router to provide a wireless network with a separate SSID to make sure that devices connect to the correct router. Both local and main wifi router were configured to provide IP address, gateway and DNS servers through DHCP.
- An old notebook was connected to the "Internet" port of the local router.
- The LAN connection of the notebook was bridged with its wireless connection. At least in all Windows versions from XP to 8 this is done by opening the adaptor options, selecting two connections and choosing "bridge these connections" (german: "Diese Verbindungen überbrücken") from the context-menu.
- The local router was configured to obtain its internet connection configuration via DHCP.
Effectively the network now behaved as if the local router was plugged into the main router via cable as a client, which also meant that the bridge-notebook was unable to use the internet or access other network devices (hence the use of a separate notebook).
The notebooks/pcs in the room now where able to connect to each other with reasonable ping times. Only one user experienced major lags, curiously the only macbook on the network. Since the internet connection to the main router was handled by a separate notebook, none of the actively used devices suffered increased latency from the internet use of other devices.
+--------+ +--------+
| Main | connects to | old |
| Router |<------------------|Notebook|
+--------+ Main wifi +---.----+
/|\
|plugged in
|by cable
|("internet" port)
+---------+ +----------+
| gaming | connect to | local |
| devices |------------------>| Router |
+---------+ local wifi +----------+
On the other hand the internet connection was slow (the equivalent of 1 MBit total across all devices), presumably due to the connection between old notebook and main router. Also such a setup would be wasteful as replacement for a permanent wifi repeater, since the old notebook had to remain online at all times. For the purpose of one evening of gaming with internet connection however it was sufficient. It is unclear if playing games against other players over the internet would have worked, since we didn't need it.